Abstract: Using seismic data recorded by 50 stations of the China Seismic Array during June 2011 to March 2013 in the study area which located in Southwestern Guizhou and Northwestern Guangxi, we got 10 seismic stations for data analysis by the shear-wave splitting snalysis method (SAM), and obtained shear-wave splitting parameters beneath the Southeastern Yunnan—Guizhou Plateau, which are the polarization of fast shear waves (PFS) and time delay of slow shear-wave. The results show that there is an apparent difference in the northern and southern areas. The PFS in Northwest Guangxi is NW—SE, which is consistent with principal compressive stress of the South China block. Southwest Guizhou is located in transitional zone of Youjiang fold belt of South China fold system and Yangtzi plate, the PFS in this area exhibits NE—SW direction, which is perpendicular to principal compressive stress of the South China block and probably affected by a series of north-east trending faults in this place. It also shows that southwestern Guizhou has a complex regional principal compressive stress and local geological structure. By comparing the time delay of slow shear-wave in southwest Yunnan—Guizhou plateau with Sichuan—Yunnan block and southeastern Cathaysia block, the crustal seismic anisotropy in Southwest Yunnan-Guizhou Plateau is similar to the South China block.

Key words: Seismic anisotropy, Shear-wave splitting, Stress direction, Southeast of the Yunnan—Guizhou Plateau